The invention relates to a device for locking a carrier carrying a cylinder in a printing machine, the cylinder being rotatably mounted in the carrier, and a pivoting lever by which the carrier is lockable to a frame.
Locking devices of this general type are used to secure the carrier and, therefore, the cylinder in a specific position in the printing machine.
For example, German Patent 634 392 describes a device for throwing a blanket cylinder on and off a plate cylinder in transfer-printing devices. If a sample or pattern is to be transferred to the blanket cylinder, the pressman places the sample or pattern into an open bearing of an outwardly swingable swinging rod, and moves the blanket cylinder with the swinging rod about a hinge thereof towards the plate cylinder that is mounted in a machine frame. A lever provided with a hook is fixed to the swinging rod. The swinging rod can be locked to the machine frame by a hook that engages behind a lug on the machine frame, and can be unlocked from the machine frame by lifting the hook out of engagement with the lug. The lever is pivotable about a pin in order to connect and release the locking members, but not while the locking action is being maintained.
The aforedescribed locking device is well suited for use in the described transfer-printing device, but cannot be used for other applications in printing machines.
It is accordingly an object of the invention, therefore, to provide a further locking device useful for several applications in printing machines.
With the foregoing and other objects in view, there is provided, in accordance with one aspect of the invention, a device for locking a carrier carrying a cylinder in a printing machine, the cylinder being rotatably mounted in the carrier, and a pivoting lever by which the carrier is lockable to a frame, comprising a pivot bearing about which the locked pivoting lever is pivotable while the locking action is maintained.
In accordance with another feature of the invention, the pivoting lever and the carrier are couplable to one another by a releasable formlocking connection. In this regard, it is noted that a formlocking connection is one which connects two elements together due to the shape of the elements themselves, as opposed to a forcelocking connection, which locks the elements together by force external to the elements.
In accordance with a further feature of the invention, the pivot bearing is adjustable so as to displace a pivot axis of the pivot bearing during the adjustment.
In accordance with an added feature of the invention, the pivot bearing is an eccentric bearing.
In accordance with an additional feature of the invention, the locking device includes a mechanism selected from the group thereof consisting of a cam mechanism and a lever mechanism, the pivoting lever being pivotable by the mechanism.
In accordance with yet another feature of the invention, the cam mechanism comprises a connecting link guide and a part guidable therein.
In accordance with yet a further feature of the invention, the cam mechanism is constructed for driving the pivoting lever in a pivoting movement about the pivot bearing, the pivoting movement coupling the pivoting lever to the carrier.
In accordance with yet an added feature of the invention, the locking device comprises a damped spring by which a pivoting lever is pivotable in a first pivoting direction for coupling the pivoting lever and the carrier in a formlocking connection, and in a second pivoting direction, by the lever mechanism, counter to the action of the spring, for releasing the formlocking connection.
In accordance with yet an additional feature of the invention, the locking device includes a drive for selectively adjusting the carrier into a first position and into a second position, respectively, along an adjustment path.
In accordance with still another feature of the invention, the drive is a pull mechanism drive.
In accordance with still a further feature of the invention, at least one further cylinder is rotatably mounted in the carrier.
In accordance with still an added feature of the invention, the carrier and the cylinder together are selectively liftable and lowerable, respectively, by the drive, in a linear and approximately vertical direction of motion, into the first position and into the second position.
In accordance with another aspect of the invention, there is provided a printing machine including at least one locking device constructed in accordance with at least one of the foregoing features.
The device for locking a carrier carrying a cylinder in a printing machine, the cylinder being rotatably mounted in the carrier, and a pivoting lever by which the carrier is lockable to a frame, is distinguished by the fact that the locked pivoting lever can be pivoted about a pivot bearing while the locking action is maintained.
The locking of the carrier to the frame is performed via a releasable positive connection of the pivoting lever either to the frame or to the carrier. The term cylinder should also be understood to include a roller.
In an advantageous embodiment further developing the invention, the pivoting lever and the carrier are couplable to one another by a releasable formlocking connection.
The releasable formlocking connection may include a hook-like end of the pivoting lever and a pin fastened to the carrier. At the end of the pivoting lever located opposite to the hook-like end thereof, the pivoting lever is mounted in the pivot bearing. The pivot bearing can, in this case, be disposed on the frame, the pivot lever being rotatably fixed to the frame by the pivot bearing. As an alternative, an engagement element, for example the pin, can also be provided on the pivoting lever, and a recess accommodating the engagement element, for example, the claw, can be provided on the frame or on the carrier.
In a further embodiment, the pivot bearing is adjustable in such a way that, during the adjustment, a pivot axis of the pivot bearing is displaced.
Two-stage locking is possible by a pivot bearing constructed in this manner. For example, in a first stage, the formlock of the releasable formlocking connection can be produced, and, in a second stage, the pivot axis of the pivot bearing can be displaced and, simultaneously, the pivoting lever can be drawn or pulled in the direction of the pivot bearing. As a result of the adjustment of the pivoting lever on the pivot bearing, a frictional fit or a further formlock additionally becomes effective between the parts forming the releasable formlocking connection, for example, a claw of the hook-like end of the pivoting lever and a pin enclosed by the claw, and secures the lock.
In a further embodiment, the pivot bearing is an eccentric bearing.
The eccentric bearing for adjusting the pivoting lever is small and takes up little space.
In a further embodiment, the pivoting lever is pivotable by a cam drive or a lever drive.
The movement of the pivoting lever during the locking action is guidable very precisely by drives of this type.
In a further embodiment, the cam drive comprises a connecting link guide and a part guided therein.
The connecting link guide can be formed with a groove or a slot, and the part guided in the connecting link guide can be constructed as a sliding block or pin or roller.
In a further embodiment, the cam drive is constructed for driving the pivoting lever into a pivoting movement about the pivot bearing, this pivoting movement coupling the pivoting lever to the carrier.
Through the intermediary of the cam mechanism, the releasable formlocking connection can be formed and released selectively either between the pivoting lever and the carrier or between the pivoting lever and the frame, depending upon the existing construction of the device, and can, for example, bring the claw into and out of engagement with the pin. The part guided in the connecting link guide can be fastened to the pivoting lever. Furthermore, other types of mechanisms and actuating drives can be used to effect this pivoting movement of the pivoting lever.
In a further embodiment, the carrier is adjustable by a drive selectively into a first position and into a second position along an adjustment path.
The cylinder mounted in the carrier can be thrown onto another cylinder mounted in the frame or thrown off this other cylinder by a throw-on or throw-off movement. The directions of adjustment of the carrier by the drive along the adjustment path, and the adjustment of the cylinder to throw it onto or off the cylinder mounted in the frame are preferably different adjustment directions.
In a further embodiment, the drive is a pull mechanism drive.
The pull mechanism drive is preferably a paired-form or form-paired pull mechanism drive, for example, a toothed belt drive or transmission or preferably a chain drive or transmission. By using such a drive, the carrier and the cylinder can be disposed in different positions with a high positioning accuracy.
In a further embodiment, at least one further cylinder is rotatably mounted in the carrier.
The first-mentioned cylinder and the further cylinder mounted in the carrier are preferably arranged with the axes thereof parallel to one another, and the outer or jacket surfaces of the cylinders are disposed in circumferential contact with one another, or have a very small spacing from one another. For example, the first-mentioned cylinder can be an applicator cylinder for applying a coating liquid to a printing material, and the further cylinder can be a metering or halftone roller assigned to the applicator cylinder and feeding the coating liquid thereto.
In a further embodiment, the carrier, together with the cylinder, can be raised and lowered selectively by the drive, in a linear and precisely or approximately vertical direction of motion, into the first position and into the second position, respectively.
This construction is very advantageous with respect to the accessibility of the unit made up of the carrier and the cylinder and in relation to the required space, if the locking device is part of a finishing unit which processes or coats the printing material, and, for example, is integrated into a varnishing unit.
The device according to the invention can be used in rotary printing machines which print web-like or sheet-like printing material and which may be constructed as an offset printing machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a locking device in a printing machine, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, wherein: